I'm done it is better than lollipop far superior than lollipop so smooth and fast also my home screen and lots of things changed iloved it marshmallow than k u @htc corporations and team it is two parts one is sense7and 2nd is 6.0.1 marshmallow..

yes i updated my desire 820 to 6.0. its working pretty fine than lollipop.
those who are getting "Corrupted file" msg. Factory reset your phone then download the software.
After up-gradation to 6.0, make a factory reset too. you ll see the actual difference in performance.
In android 6.0 , missing "internet pass through" mobile network sharing option. i was using that in lollipop. (disappointed.)

Got marshmallow update yesterday.. first part downloaded and installed properly Bt the 2nd part of 1 gb after downloading said update is corrupt...
Done that twice with no change..
Can anyone suggest what to do..